FDFD Settings

This section describes the settings for FDFD solvers.

Select the FDFD button in the Home tab and click any empty space in the Composite viewer to create an FDFD solver. Then modify the settings of the FDFD solver in the automatically pop-up Edit properties interface to complete the addition of the FDFD solver.

FDFD Solver Settings

General Settings

The General tab is used to set the simulation space (including simulation and geometric dimensions) for the solver.

Simulation Dimension

The Dimension and polarization tab is used to set the simulation dimensions for the FDTD solver.

Name	Description
2D Polarization	TE: TE-polarization, for example: including three components $E_z$ , $E_x$ , $H_y$ ; TM: TM-polarization, for example: including three components $E_y$ , $H_z$ , $H_x$ .
2.5D	2.5D simulation.

Geometry

The Geometry tab is used to set the size parameters of the FDTD solver.

Name	Description
Z/X/Y pos	Set the center of the solver.
Z/X/Y span	Set the scope of the solver.

2.5D Settings

The 2.5D settings tab is only enabled when the simulation dimension is set to 2.5D.

For detailed parameter settings, see 2.5D settings.

FDFD

The FDFD tab is used to set the wavelength and frequency of the simulation and select the material sampling type.

The Wavelength/Frequency tab is used to set the wavelength and frequency of the simulation.

Material Sampling

In the FDFD solver, different frequency sampling methods can be selected for material data corresponding to different material types.

Sampled material sampling type

For sampled materials, the material data is discrete data at different frequencies, and there are two sampling methods:

Name	Description
Linear interpolation	When applying the Linear interpolation to acquire material data at different frequencies, the resulting material data may have discontinuities in frequency.
Fit model	Use a polynomial material model to fit and obtain Sampled material data at different frequencies.

Analytic material sampling type

For analytic materials, material data is calculated directly from physical formulas, such as Debye, Drude, Lorentz models, etc. There are two sampling methods for material data at different frequencies:

Name	Description
Analytic model	Use the dispersion model of the Analytical material to calculate data.
Fit model	Use a polynomial material model to fit and obtain Analytic material data at different frequencies.

When the Fit model is selected as the Material sampling type, the menu bar of Fit bandwidth is editable.

Background Material

The Background Material tab provides the Background Material drop-down menu for users to select background materials.

Name	Description
Background material	The background material library, including materials from the Global library. You can also use the Add/Edit in the Project library to create project-specific materials as background materials

After selecting a background material, its relevant information (Name, Type, Last modified, etc.) is displayed simultaneously.

Mesh

The Mesh tab provides the mesh settings for solvers.

For detailed parameter settings, see Mesh.

Boundary Conditions

The Boundary conditions tab provides the boundary condition settings for solvers.

For detailed parameter settings, see Boundary Conditions.

Advanced Settings

The Advanced tab provides the advanced settings for solvers.

Name	Description
Force symmetric x/y/z mesh	Forced mesh symmetry in the x/y/z direction. Only the positive-axis half of the simulation region needs to be considered; the mesh of the negative-axis half replicates that of the positive-axis half. This option allows generation of simulation meshes based on user-defined wavelength ranges.